This invention relates to a keyboard musical instrument and, more particularly, to a keyboard musical such as acoustic pianos and composite keyboard musical instruments fabricated on the basis of the acoustic pianos.
FIG. 1 shows a typical example of the acoustic piano. The acoustic piano is classified in the grand piano. The prior art grand piano includes a piano case 1, legs 2 and a pedal system 3. Although a keyboard, action mechanism, hammers, dampers and strings are installed inside the piano case, these component parts are not seen in the figure. The legs 2 downwardly project from the piano case 1, and maintain the piano case and, accordingly, component parts over the floor.
The pedal system 3 is associated with the dampers and the keyboard. When a pianist actuates the pedal system 3, the pedal system 3 keeps a damper or dampers spaced from the strings, and makes the keyboard and, accordingly, the hammers slightly offset from the associated sets of strings. As a result, the tone or tones are prolonged or lessened. Thus, the pianist changes the loudness of tones and the length of tones by using the pedal system 3.
The pedal system 3 includes a lyre box 4, pedals 5A/5B/5C, pedal rods 6 and pedal posts 7. Although a lyre block is fixed to the lower surface of the key bed, which defines the bottom of the piano case 1, the lyre block is not seen in the figure. The lyre box 4 and pedal posts 7 are formed of wood. The pedal posts 7 are fixed to the lyre block, and downwardly project from the lyre block. The lyre box 4 is fixed to the lower ends of the pedal posts 7, and are hung from the piano case 1. The pedal posts 7 are so rigid that users can not change the distance between the lyre block and the lyre box 4.
The pedals 5A, 5B and 5C are called as xe2x80x9cdamper pedalxe2x80x9d, xe2x80x9csostenuto pedalxe2x80x9d and xe2x80x9csoft pedalxe2x80x9d, respectively. Tough not shown in the figure, the pedals 5A/5B/5C are turnably supported inside the lyre box 4, and projects through holes formed in the front panel of the lyre box 4. The pedal rods 6 are connected at the lower ends thereof to the rear portions of the pedals 5A/5B/5C and at the upper ends thereof to the dampers and the keyboard.
A chair is put on the floor in front of the piano case 1, and a pianist sits on the chair for fingering on the keyboard. While the pianist is fingering a piece of music on the keyboard, he or she steps on the pedals 5A/5B/5C at appropriate timing so as to prolong and/or lessen the tones. The pedals 5A/5B/5C are depressed by his or her right foot and left foot. For this reason, the distance between the lyre block and the lyre box is adjusted to a certain distance longer than the shank of a standard adult.
A problem is encountered in the prior art grand piano in that the distance between the lyre block and the lyre box is too long for children. The chair is usually regulable in height between the floor and the cushion. When a child practices fingering, the cushion may be lowered. Then, the child can step on the pedals 5A/5B/5C. However, the keyboard becomes too high for the child. A pedal system is also incorporated in an upright piano, and the pedals are adjusted to adult players. Thus, the prior art acoustic pianos are designed to be played by adults, and children are not taken into account.
A solution has been proposed. The solution is disclosed in Japanese Utility Model application laid-open 59-158190 and Japanese Patent Application laid-open No. 9-44145. Assistant pedal systems are disclosed therein. The assistant pedal system is attached to the pedals 5A/5B/5C. The child steps on the assistant pedal system, and the assistant pedal system replays the foot action to the pedals 5A/5B/5C. Thus, the assistant pedal system permits the child to play the grand piano designed for adults.
However, various problems are encountered in the assistant pedal systems. First, the assistant pedal systems have complicated structures, and, accordingly, are expensive. The prior art assistant pedal systems are to be regulable in the distance between the pedals 5A/5B/5C and the assistant pedals, because the children have their own shanks different in length. If the distance between the pedals 5A/5B/5C and the assistant pedals was not regulable, the prior art assistant pedal system would merely take up the different between the shank of the standard adult and the shank of a standard child. In order to permit users to regulate the distance between the pedals 5A/5B/5C and the assistant pedals, the prior art assistant pedal systems have regulating mechanisms, and the regulating mechanisms make the prior art assistant pedal systems complicated and expensive.
Another problem is that malfunction is liable to take place. While a child is playing a piece of music on the keyboard, the prior art assistant pedal system is expected to keep the linkage between the pedals 5A/5B/5C and the assistant pedals stable. On the other hand, it is appreciated for the users to attach the prior art assistant pedal mechanism to and detach it from the pedals 5A/5B/5C easily. If a simple coupler is used in the prior art assistant pedal system, the prior art assistant pedal system is liable to be disengaged from the pedals 5A/5B/5C, and the child discontinues the practice, and attaches the prior art assistant pedal system to the pedals 5A/5B/5C, again. Meanwhile, if the prior art assistant pedal system is strongly attached to the pedals 5A/5B/5C, the complicated assembling and disassembling works would wear his or her temper to threads.
Yet another problem is that the prior art assistant pedal system damages the external appearance of the acoustic piano. Users may like electronic keyboard with modern appearance. However, the users expect the acoustic pianos to have the classical features. When the prior art assistant pedal system is attached to the pedal system 3 of the acoustic piano, the external appearance is curious, and is far from the classical feature.
It is therefore an important object of the present invention to provide a keyboard musical instrument, which is appreciated by both adults and children without any damage to the external appearance.
In accordance with one aspect of the present invention, there is provided a keyboard musical instrument comprising a case having an inner space, a keyboard mounted on a flat board of the case and exposed to a player, an internal mechanism including an action mechanism linked with the keyboard and actuated when the player depresses keys of the keyboard, hammers associated with the keys, respectively, and driven for rotation by the action mechanism when the player depresses the associated keys, beaten members provided in association with the hammers and struck with the hammers at the end of the rotation and a damper mechanism linked with the keyboard and driven by the keys so as to influence vibrations of the beaten members, and a pedal mechanism including plural pedals depressed by the player for changing attributes of tones to be generated when the keys are depressed, a foundation on which the plural pedals are rotatably supported, plural connectors connected between the plural pedals and the internal mechanism for transmitting motion of the pedals to the internal mechanism, a mechanism provided between the case and the foundation and permit the foundation to move with respect to the case and a coupler provided for the foundation and changed between a releasing position for permitting the foundation to move with respect to the case and a fixing position for prohibiting the foundation from changing the position thereof with respect to the case.